Repair and modify dentures and appliances


This unit of competency describes the skills and knowledge required to reline, rebase, repair and modify removable prostheses.

This unit applies to work in dental technology.

The skills in this unit must be applied in accordance with Commonwealth and State/Territory legislation, Australian/New Zealand Standards and industry codes of practice.

Elements and Performance Criteria



Elements define the essential outcomes

Performance criteria describe the performance needed to demonstrate achievement of the element.

1. Prepare case

1.1 Apply standard precautions when receiving, handling and working on dentures and appliances

1.2 Decontaminate dentures and appliances according to infection control guidelines

1.3 Read and correctly interpret work order

1.4 Examine fractured components for defects

1.5 Realign, position and secure fractured components in their correct relationship

2. Prepare model

2.1 Construct model according to the work order.

2.2 Construct articulation key

3. Repair denture or appliance

3.1 Prepare and shape denture surfaces to allow for bonding with the new material

3.2 Relocate components

3.3 Select and prepare materials and processing equipment

3.4 Apply repair materials using the correct technique to the required shape and thickness

3.5 Process materials according to manufacturers’ instructions

4. Modify denture or appliance where required

4.1 Decontaminate impressions according to infection control guidelines

4.2 Pour the model material into the impression in accordance with accepted techniques

4.3 Articulate case and transfer records, or construct articulation key as required

4.4 Prepare denture or appliance surfaces appropriately for the modification to be made

4.5 Reline, re-base or modify the denture in accordance with work order

5. Trim, shape and finish denture or appliance

5.1 Trim denture or appliance to relevant anatomical outline or required extension of the base

5.2 Examine the tissue fitting surface and remove any processing anomalies and sharp surfaces

5.3 Refine and polish surfaces and produce required contours

5.4 Evaluate the finished prosthesis

5.5 Decontaminate the appliance according to infection control guidelines

5.6 Place the appliance in a sealed container for dispatch

Evidence of Performance

The candidate must show evidence of the ability to complete tasks outlined in elements and performance criteria of this unit, manage tasks and manage contingencies in the context of the job role. There must be evidence that the candidate has:

• read and correctly interpreted 1 work order and manufacturers’ instructions for repair and modification of removable prostheses, and used standard precautions and safe work practices for constructing repairs and modification for a maxillary or mandibular denture with a combination of the following:

- replace, add or modify new or existing artificial teeth

- replace, add or modifying new or existing metallic components

- modify the denture base

• critically evaluated the 1 repaired or modified denture produced to meet technical laboratory and patient requirements, including confirming that the repaired or modified denture:

- is compliant with the work order

- is free from defects

- is functionally effective in line with the design

- is suitable for insertion in the mouth.

Evidence of Knowledge

The candidate must demonstrate essential knowledge required to effectively complete tasks outlined in elements and performance criteria of this unit, manage tasks and manage contingencies in the context of the work role. This includes knowledge of:

• Australian/New Zealand Standards, workplace health and safety (WHS) policies, Dental Board of Australia guidelines on infection control, Commonwealth and State/Territory legislation and organisation policies relating to dental laboratory work

• fundamental oral anatomy including:

- dentition – arrangement of the teeth, naming and coding of teeth

- structures of the oral cavity – hard and soft palate, lateral and posterior borders of the oral cavity, tongue and floor of the mouth

- teeth form and function

• constructional faults that cause fractures of denture base including:

- absence of balanced occlusion

- inadequate polymerisation times and temperatures

- incorrect dough consistency when packing

- incorrect positioning of maxillary posterior teeth

- insufficient thickness of acrylic resin in the anterior palatal region of the denture

- rapid cooling after processing

• constructional faults that cause broken teeth

• denture base materials

• denture decontamination procedures when modifying acrylic

• methods for modifying, repairing and maintaining removable prostheses.

Assessment Conditions

Skills must have been demonstrated in a dental laboratory workplace or in a simulated dental laboratory environment that reflects workplace laboratory conditions. The following conditions must be met for this unit:

• use of suitable facilities, equipment and resources including:

- access to work order

- Dental Board of Australia guidelines on infection control on which the candidate bases the planning process

- laboratory safety manuals and standard operating procedures in line with relevant Commonwealth and State/Territory legislation

- WHS policies on which the candidate bases the planning process.

Assessors must satisfy the Standards for Registered Training Organisations (RTOs) 2015/AQTF mandatory competency requirements for assessors.

Foundation Skills

The Foundation Skills describe those required skills (language, literacy, numeracy and employment skills) that are essential to performance.

Foundation skills essential to performance are explicit in the performance criteria of this unit of competency.